使用Guava的RateLimiter完成简单的大流量限流详解编程语言

package ratelimiter; 
 
import com.google.common.util.concurrent.RateLimiter; 
import org.springframework.stereotype.Component; 
 
import java.util.concurrent.ExecutorService; 
import java.util.concurrent.Executors; 
import java.util.concurrent.TimeUnit; 
 
/** 
 * @author xfyou 
 * @date 2018/10/31 
 */ 
@Component 
public class AccessLimitService { 
 
    private static volatile int acquireCount = 0; 
    private static final Object OBJECT = new Object(); 
 
    /** 
     * 每秒可以获得50个许可证 
     */ 
    private RateLimiter rateLimiter = RateLimiter.create(50); 
 
    private boolean tryAcquire() { 
        // 等待1秒钟如果未能获取到许可证就返回false，否则返回true 
        return rateLimiter.tryAcquire(1, 1000, TimeUnit.MILLISECONDS); 
    } 
 
    public static void main(String[] args) { 
        AccessLimitService accessLimitService = new AccessLimitService(); 
        ExecutorService executorService = Executors.newCachedThreadPool(); 
        for (int i = 0; i < 1000; i++) { 
            executorService.execute(new Runnable() { 
                @Override 
                public void run() { 
                    if (accessLimitService.tryAcquire()) { 
                        System.out.println("获取许可证，执行业务逻辑。"); 
                        synchronized (OBJECT) { 
                            System.out.println(++acquireCount); 
                        } 
                        try { 
                            Thread.sleep(20); 
                        } catch (InterruptedException ex) { 
                            // 
                        } 
                    } else { 
                        System.err.println("未获取到许可证，请求可以丢弃。"); 
                    } 
                } 
            }); 
            try { 
                Thread.sleep(1); 
            } catch (InterruptedException e) { 
                e.printStackTrace(); 
            } 
        } 
        executorService.shutdown(); 
    } 
}